Hesitates after checking compress. - leaves many clues. Honda Accord

I'd checked compression days ago and now it hesistates. When I made 184 psi on cylinder three I realize that I didn't disconnect the power to the fuel pump or ground the coil wire as instructed by the manual, I quit. Now I'm haunted with a bad miss on cylinder three, cold or warm and sometimes stalling when put in gear. Both O2 sensors read 0.9V at 4K rpm and 0.3V when throttle releases, they're okay according to a service manual. Sparks aren't as bright.

I unplug the fuel injector connector number three, let it idle and no miss. I put connector back in, put in another spark plug and start the car and find a miss. Fully warm, I go for a drive, it hesitates. I open the hood, disconnect the cold start sensor (aka, coolant temp sensor) and everything is all fine. What could be wrong?

TIA, Waltson, `89 Honda Accord 270K, well maintained.

Reply to
Tibur Waltson
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More details: Today, I test drive and find no miss for the first 1 minute of cold start in the morning. The spark plug is white - no black soot or gunks. Clamped an induction timing light on this wire shows a miss every six revolutions. Timing is adjusted to spec. Disconnecting the cold start sensor is now not fine. T. Waltson

Reply to
Tibur Waltson

It sounds like you pretty much have it narrowed down here. I would say to try calling the dealer and asking them what it could be. It sounds to me like the problem is before where you hook up the induction timing light, as you are getting this result. Have you tried moving the light up further in the circuit to isolate the problem even further? In other words if you trace it back until it doesn't skip every 6 revolutions, you have likely found your problem and thats where I would replace the part. I would also call the dealer (or better yet actually go there face to face )and see if they can give you any ideas. Most are pretty friendly and offer help. Another thing you might try is a local repair shop. The place I bring all my vehicles when I can't do the work myself gives me a world of knowledge. Good luck and let us know how you make out.

Fwed

Reply to
fweddybear

Fwed, you are certainly inhaling way too much of your own smoke.

Reply to
MaxAluminum

Why were you checking the compression in the first place? Did you have a miss? And was it #3? I think your diagnostic methods are suspect. You disconnected one injector and got no miss! Hardly. Find the specs for the coolant sensor and check that just as a side item. Sounds like a secondary ignition problem. If the wires are more than 5 years old why not replace them? Maybe you have a coil pack that is breaking down when it warms up. Work on the secondary ignition and forget the injector for now.

Reply to
MaxAluminum

Problem solved. See below.

Noted. Disconnecting injectors will cause rough idle, I'm sure, but this is eliminated from the equation. No miss meaning no drop-out every 6 cycles. The car can idle on 3 cylinder at 600 rpm. A miss would stall the vehicle. No miss found on 1,2, and 4.

3.8K-Ohm cold, normal.

The oem spark plug wires, spark plugs, caps, rotors are 1.5 years old. The coil wire, 10-years.

Possibly.

A friend offer to check compression as he passed by. The car being 270K mi, I would be happy to.

I suspect so.

Recap. Disconnecting injector three finds no miss. Disconnect others will stall. Connect T-light finds a missing spark on #3. Notice that I didn't use fresh plugs during diagnostics. After replacing with four fresh plugs the problem is gone and after rigorous testing. Fingers cross.

Plug type used previously: Denso OEM Plug type in use currently: Denso OEM Plug type will be using: Autolite aftermarket. Certain type Autolite plugs have proven more reliable. I've never seen more than one die after exposed to gasoline and severe compression. There will be a complete tune-up forthcoming. Thanks all. T Waltson

Reply to
Tibur Waltson

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